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Comments 124801 to 124850:

  1. The role of stratospheric water vapor in global warming
    Using the running mean as a guage, measurements of methane show it leveled off from 1999 to 2002, rose again peaking in 2003 followed by a drop returning to roughly 2002 levels. This was followed by a shallow bump in 2006. A point of concern is that in 2007 the rise observed prior to 1999 began to continue. Currently NOAA is reporting that we've exceeded 1800ppmv for methane. You can read NOAA's AGGI report ( updated Sept 09) here http://www.esrl.noaa.gov/gmd/aggi/ You can also read about terrestrial stores of methane here - http://www.nature.com/climate/2009/0904/full/climate.2009.24.html If I am not mistaken Nature Reports Climate Change is free to download.
  2. The role of stratospheric water vapor in global warming
    Yet from my reading of it, the rise in stratospheric water vapor, irrespective of its radiative forcing potential, seems to have its likely origins in the oxidation of anthropogenic methane. If this is correct, then in my opinion this paper actually *supports* anthropogenic global warming even more.
  3. The role of stratospheric water vapor in global warming
    The abstract from Solomon 2010 states: 'More limited data suggest that stratospheric water vapor probably increased between 1980 and 2000, which would have enhanced the decadal rate of surface warming during the 1990s by about 30% compared to estimates neglecting this change.' 30% is pretty substantial by any standard bearing in mind that we have systems that are very sensitive to positive and negative feedbacks. It's all the more interesting considering that 1998 seems to have been an exceptionally warm year (whether because of ENSO or other causes) with evidence of subsequent relative cooling. Marcus, the reported levelling off of methane levels is surely very worthy of note given its reported significance as a greenhouse gas. We are dealing with complex systems which we do not undertsand well. With respect, the gratuitous references to 'contrarians' and 'denialists' that often appear on this site have a quasi-religious flavour which are out of keeping with the spirit of genuine scientific enquiry.
    Response: I am making more effort to moderate the labelling and ad hominem comments in order to maintain scientifically constructive dialogue. Consequently, I've been deleting a great number of comments lately (from both sides of the debate). I think we all need to take a deep breath and calm down a little. Not because this isn't an important issue but because this is such an important issue.
  4. The role of stratospheric water vapor in global warming
    Thing is, though, that it only *started* to level off-it was still rising right up until 2000-2001, though at a slower rate from 1992-2000 than in 1980-1992. Given that methane has a half-life of 7 years, then I think it's perfectly in line with observed drop in stratospheric water. Lets not also forget that the other by-product of methane oxidation is carbon dioxide-another greenhouse gas.
  5. The sun is getting hotter
    The section on independent tests is really good showing multiple measurements and proxies for TSI, with solid agreement. Are you aware of any measurements over the 1990-92 period using radio wavelengths (eg 10.7cm) that would also serve as a calibration? BTW, you wrote Challenge instead of Challenger.
    Response: Fixed the Challenger typo, thanks for the tip.
  6. Lessons from the Monckton/Plimer debate
    @61 shawnhet Yes, one can attempt to reconcile Plimer (non-anthtro forces have changed climate by large amounts in the past) with Monckton (sensitivity to forcing is low) by suggesting that past climate change has required strong forcing. But, the obvious question is then "what strong forcings"? Nothing in physics or paleontology would suggest that our sun has varied its output by enough to force the glacial periods. The most clever idea I heard for such a forcing was cosmic rays causing significant albedo changes by stimulating cloud formation. But recent measurements almost certainly rule that out. The thing is, the glacial/interglacial periods do line up rather well with forcing from Milankovitch cycles - and those forcing are weak. So there'd have to be a strong forcing we can't detect (nor apparently imagine) that just happened to operate at the same times as Milankovitch cycles. It makes a heck of a lot more sense to conclude that sensitivity is high, and there are no significant forcings we haven't thought of.
  7. The role of stratospheric water vapor in global warming
    Methane started to level off in early 1990s so not tight correlation with water vapor. Also, apparently (though I too am limited by article access issue) ∆ in strato-water vapor was in lower stratosphere thus not likely methane. All that said if there was a change in tropo-strato exchange then there might be noticeable change in atm concentrations of methane, SF6, etc. Worth looking into...
  8. The role of stratospheric water vapor in global warming
    Hmmm, as I recall, methane levels rose sharply through the 2nd half of the 20th century-but leveled off between 2000-2008. So maybe that's why there's a drop in stratospheric water vapor post-2000. However, as this additional methane was derived from human sources (sewerage, land fill, fossil fuel extraction, land-use change)-then the stratospheric water vapor contribution to global warming-small though it might be-might well still be ultimately of anthropogenic origin. That certainly doesn't let the contrarians off the hook!
  9. The role of stratospheric water vapor in global warming
    The article is hidden behind a pay-wall so I have to rely on the likes of yourself to interpret. Even if I could access the article there is no guarantee I could understand it. It is interesting. Thanks.
  10. There's no empirical evidence
    samantha, it's basically the same, they just found it hard to get it through peer review.
  11. Lessons from the Monckton/Plimer debate
    Also, I sincerely doubt that the amount of atmospheric warming which could be generated from an artificial lake can even remotely compare to the atmospheric warming that a greater than 100ppm rise in CO2 could cause.
  12. Lessons from the Monckton/Plimer debate
    Um, its DAMS, not DAMNS-you only say DAMN if you're cussing ;).
  13. There's no empirical evidence
    Riccardo Thanks for the link. I will look over it. BTW. The original paper is two years old, this paper is Jan2009.
  14. It's Urban Heat Island effect
    pedex, i'm not an expert but there are a few things i know. Comparing the raw data has no meaning. Comparing adjusted data from two nearby stations, one rural and one urban, tells us that the UHI effects exists, which we all know and it's corrected for. Full analysis, with homogenization, averaging and gridding separately the data from urban and rural station would be requied, which i'm not able to do by my self and that you have not done either. I'm left with the published papers by professionals, in part referenced in this blog post. If ever someone will come up with a serious demonstration of the fault in the current analysis, which incidentally appears to be in agreement with satellite data (no UHI effect there), i'm ready to listen. For sure i'm not going to trust anyone who in its spare time play around with a computer and a bunch of meaningless (to him) numbers, the whole story is far more serious than just this.
  15. It's Urban Heat Island effect
    Ive done some plots both ways, the old fashioned manual way and using the site I linked above, the result comes out the same. Rural stations tend to show no warming, urban stations do. It is especially evident in the US as well where there is lots of space between cities and lots of rural areas. Some places like the city where I live you can literally see the warming correlate with the development of the city where nearby rural stations show none at all. Like I said, plot some of your own and see what you get. Don't take my word for it or the word of this website because its arguments are pretty disingenuous in their own right from what I have seen.
  16. It's Urban Heat Island effect
    pedex, strange that the missing data come mostly from the last few years. It may generate large errors also in the previous years. The very first step should be to check the code, no one is going to trust those numbers so blatantly wrong.
  17. It's Urban Heat Island effect
    when a data point is missing an entry the ghcn data puts in a -9999 to show it, the software averaged that in and also tried to plot it which puts if off the chart its supposed to filter those out but for some reason it doesn't at the end of beginning of a plot sometimes
  18. It's Urban Heat Island effect
    pedex, it's not only the running average that has that weird drop, the blu curve drops as well. There must be something wrong in how the data are processed. However, the simple average of stations doesn't tell you much. More so if you compare unadjusted data (the 778 stations) with adjusted data (the 173 stations).
  19. Lessons from the Monckton/Plimer debate
    RSVP at 05:40 AM on 1 February, 2010 "The point here was not to condemn hydroelectric power, it was simply to state that even damns must be contributing in some way to global warming." What is really interesting about dams is the damping effect they've had on sea level rise. It is of course a temporary effect. More...
  20. Lessons from the Monckton/Plimer debate
    Philippe Chantreau Just kidding that you advanced this idea, but your comment did hatch the thought. Think about the difference from snow melt discharging into the sea within a season vs. being held back all year in a damn. If incremental CO2 levels can make so much difference for narrow bands of IR, why not direct solar radiation trapped in incremental H2O? It may not be "causing" global warming, but it cant be helping. Now, as far as global warming, it may not be as bad as other forms of power generation, and the benefits to water supplies cannot be overlooked etc. The point here was not to condemn hydroelectric power, it was simply to state that even damns must be contributing in some way to global warming. (As far as salmon and trout. Damns completely mess up ecosystems and deter salmon from reach their spawning grounds. Special fish ladders have to be arranged, but damns on the whole have decimated natural fish populations. And yes, the water below damns can be cold when taken from the bottom, but the fish found there are planted for fishermen. )
  21. It's Urban Heat Island effect
    just how the software cuts off at the end of the record, its normal when you do a running average like that software does you will see a messed up end and beginning of the graph if the data set is missing a value if you go to the noaa website and download the data you will see lots of stations that have data dropouts which when that software at the other website above gets one of those at the end or beginning of the graph it will blow up or in this case down, what is important is the long term trend ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/ you can plot all sorts of stuff from that data, temps gridded or not, adjusted or not, a couple data sets to choose from as well as precipitation amounts as well I think everyone should do a few, pick your home town and have a look, pick some rural stations and urban ones and graph them and see how they look. You might be surprised at what you see. I would also recommend just for your own sanity do a few single station plots and look up what the actual stats are for that station as far as where it is and what kind of quality it has. They are labeled as to what kind of local situation they are in like wooded or grassy plains etc etc.
  22. It's Urban Heat Island effect
    pedex, what is that 9 °C drop in temperature in one of your graphs? Looks weird.
  23. It's Urban Heat Island effect
    ^^typo, the exclusion should be after 2000 not 200
  24. It's Urban Heat Island effect
    http://home.rr.com/pedex252 two graphs on that site, one is 177 urban stations using adjusted data from the GHCN data set with stations w/o data before 1930 and after 200 excluded the other is 778 rural stations with same exclusions sorry guys but the data disagrees with the explanation made here on this site and it matters not whether adjusted or unadjusted data is used all that matters is whether or not you pick urban or rural stations if you wish to make your own graphs then go here: http://www.appinsys.com/GlobalWarming/climate.aspx some of you should plot some for yourselves and see what you get instead of taking my word for it or anybody else's for that matter
  25. Philippe Chantreau at 03:27 AM on 1 February 2010
    Lessons from the Monckton/Plimer debate
    Advancing what idea? Care to provide some scientific references? How seriously did you think about this RSVP? The water "sitting" during the winter actually has a lot more time to loose heat to the atmosphere and that's also the time where the water level will be the highest. However, the large thermal mass of an artificial lake makes it not so easy to warm or cool. During the spring, gathering melt water in large bodies is actually a excellent way to prevent it from warming. All in all, is there a net effect? How big can it possibly be? Considering the volumes released by dammed rivers and that of the oceans as whole, could this effect be measurable at the oceans' scale? Do you realize that the chance for the oceans to be be heated in any significant way by the "effect" you describe is so remote that the idea is downright ludicrous? And exactly how many "kinds of solar energy" can you list? Let me guess, you were joking, of course, silly me. You were, right? If you really wanted to do rethoric for its own sake, you could have gone about the CO2 related to concrete production, transportation, the "damns" construction process and what not. That would have been easier to exploit. Of course, then you'd have to exactly quantify that and come up with a number of years-equivalent-coal and try to convince that the "damns" weren't worth it, which they were. That wouldn't be OT either, since it is pretty close to the Monckton/Plimer style of "debate."
  26. Lessons from the Monckton/Plimer debate
    RSVP said:
    Water in damns (sic) sits there picking up all kinds of solar energy and then gets released into the oceans.
    RSVP, you don't know very much about dams and the temperature of water in them. Anyone who is a fly fisherman in the western US will know about the world class trout fisheries which have established them selves down stream of a number of large dams. Previously, the water in these rivers had been too warm to support various trout species (the fish that western fly fishers are looking for) but after the dams were in use the water discharging through the turbines was very cold and supported both trout and the insects which the trout fed on. The best dams are the so called bottom discharge dams but other dams are helpful too. The water soon warms up down stream and the trout only inhabit a few miles of newly established prime habitat down stream from the damns. So much for your theory. Google "tailwater fisheries" to see how wrong you are.
  27. Guest post in Guardian on microsite influences
    I didn't go through the paper accurately yet and maybe i will contradict myself later :). But there are a few things that i feel can already be stressed It is not on the water vapour feedback. Indeed, it focuses on the water vapour just in the lower stratosphere; it might have contributed to the slow down of the tropospheric temperature (as opposed to global warming) increse, but it's something related more to interannual/decadal variability than to the long term trend. The reason of the sudden drop in year 2000 is not clear. It might be related to the unusual warming of the western pacific ocean and the drop of the tropopause temperature. If this is linked to global warming or it is part of a natural cycle can not yet be assessed. As far as i know no one has looked at models behaviour as far as the lower stratospheric humidity is concerned. It's then hard to guess a possible physical mechanism responsible for its reduction and if it's a consequence of the already known physics. Gavin Schmidt at RealClimate promised further analysis, we'd better wait for more insights. As is standard practice in science, unless there are evident flaws in a paper (which seemes to be not the case here) it should be carefully evaluated taking the required time. No nails in the coffin nor smooking guns around, just one more little piece of evidence to fit in the global picture.
  28. Guest post in Guardian on microsite influences
    Iodolite, Solomon's new stratospheric water vapor paper is discussed at RealClimate.
  29. Guest post in Guardian on microsite influences
    This is off topic but I can't find anyone discussing Susan Solomon's (NASA)new study showing that water vapour is decreasing in the stratosphere. She says that water vapour is acting as a negative feedback rather than amplyfiying CO2. http://www.guardian.co.uk/environment/2010/jan/29/water-vapour-climate-change says no one understands why its decreasing
  30. Trenberth can't account for the lack of warming
    Thank you very much for the excellent explanation. One point still puzzles me, though, perhaps because I’m Italian: the word “travesty”. According to my good old Oxford Dictionary it means “a description that intentionally misrepresents the original e.g. burlesque poem etc.” etymology being the Italian verb travestire = disguise. It somehow conveys the impression that the whole thing is a farce, a dress up, an attempt to deceive. I understand in private informal correspondence one doesn’t care much about wording, but, why didn’t he use pity or shame or bad luck?
  31. Lessons from the Monckton/Plimer debate
    Albatross at 16:19 PM on 31 January, 2010 "In the one ad the were saying that the globe has been cooling for the last ten years. Yet in the second ad they claimed that the observed warming was because of the sun! Well, please do make up your mind. But as transparent as these ads may be to scientists, the ads worked and were very effective at confusing people and forming public opinion." Presumably crafted, tested and confirmed to cause severe confusion, leading to "Oh, those scientists can't even make up their minds." Doubt and confusion, purchased in bulk. That is seriously appalling.
  32. Lessons from the Monckton/Plimer debate
    #45 "Philippe Chantreau at 03:33 AM on 31 January, 2010 Keep your hasty judgments to yourself RSVP, my computer is powered by hydro." Hydroelectric power is derived from man-made damns that essentially act as solar collectors to heat our oceans. In nature, rivers would normally carry water directly to the sea with minimum heating. Water in damns sits there picking up all kinds of solar energy and then gets released into the oceans. Thank you for advancing this idea.
  33. Lessons from the Monckton/Plimer debate
    Monckton and Pflimer do not only contradict each other, they often contradict themselves. This seems to be a common theme of those in denial and of those who choose to try and muddy the waters. A case in point, recently the "Friends" of Science in Canada ran two misinformation ads across the country. In the one ad the were saying that the globe has been cooling for the last ten years. Yet in the second ad they claimed that the observed warming was because of the sun! Well, please do make up your mind. But as transparent as these ads may be to scientists, the ads worked and were very effective at confusing people and forming public opinion. Marcus made the very good point @65 that the observed cooling of the stratosphere is not consistent with the argument put forth by Monckton that the TSI is increasing; not only that but Monckton is making that claim while at the same time claiming that the sun governs global SATs and that the globe has not warmed for 15 years. In contrast, Plimer claims that this warming is just part of a natural warming cycle. Or they concede that it is warming and that anthro CO2 is partly to blame, but don't worry, climate sensitivity is not as high as claimed (despite overwhelming evidence to the contrary) so there is nothing to worry about. So on and so forth it goes. These guys are all over the map, and I do believe that they do so on purpose, because their chameleon-like behavior allows them to adapt to the question and/or the crowd and then pluck the 'answer' which they think best fits the situation and/or question at hand, knowing full well that the lay person will never be able to keep up with their continued and varied deception. Monckton especially seems to live in a land of opinion and rhetoric, and very few of his comments are grounded on solid, reputable science. He may be able to work a largely uninformed crowd at a public gathering, but that is no substitute for science. I challenge Monckton and Plimer to give a talk at the annual AGU, AMS or RMS meetings and to allow at least 60 minutes for questions, and for the entire "debate" to be recorded on video. We all know the modus operandi of Monckton and Plimer is to confuse and distract and never concede. The last point is especially annoying because reputable scientists or groups like the IPCC correctly issue corrections or concede if their work is not supported by their peers or latest science, or does not satisfy the unrealistic perfection demanded by the 'skeptics'. Monckton et al. answer to no one it seems when it comes to factual correctness-- their double standard and hypocrisy is astounding. Regrettably, their rhetoric seems to resonate with many, and when viewed in isolation can be convincing. What is truly saddening and alarming is that the media are not taking Monckton et al. to task on their hopelessly sloppy pseudo science. Monbiot has, but he is in the minority. It is easy for professional climate scientists to dismiss Monckton or Plimer as cranks, but that is not enough. The Monckton's of the world need to be repeatedly subjected to the same scrutiny and standards on the world stage that they love to demand of others. Blogs help, but in the end one needs the media on board, that is how one reaches the masses, and there are sadly far too few reputable journalists or media outlets out there right now who seem motivated to do so. Just where are the critically minded media and journalists on this file, and what is the infatuation with reporters like David Rose with those in denial about AGW? How do we turn this around so that journalists are more interested in the pursuit of truth and science rather than fawning over contrarians?
  34. Lessons from the Monckton/Plimer debate
    Re @64, John Cook, sorry and thank you for adding the links. I'll try and be more diligent in providing links in future.
  35. Lessons from the Monckton/Plimer debate
    EdB, the HS is not broken. You simply do not understand. Mann et al. (2008) implemented the recommendations of the reports (including those of Wegman) and it did not significantly change the results and especially not the conclusions. Also look at Mann et al. (2009). You can look at temperature reconstructions determined using ice core data, bore hole data, lake sediment data and ocean sediment data etc. and they all have a distinct Hockey Stick shape. Does that not tell you something? The Hockey Stick is alive and well, it is really just that simple.
  36. Peer reviewed impacts of global warming
    Riccardo, Thanks for the link. Fascinating reading and shows how complex it all is at the micro level. I'll read up again on the earth tilt stuff in my reference book of choice - 'A Rough Guide to Climate Science'
  37. On the reliability of the U.S. Surface Temperature Record
    Tom Dayton at 11:41 AM on 31 January, 2010 "A second post on D'Aleo and Watts from the Texas State Climatologist. " Pretty clear why he's got his post. Ability plus communications skills in abundance. That was very interesting, thank you.
  38. On the reliability of the U.S. Surface Temperature Record
    A second post on D'Aleo and Watts from the Texas State Climatologist.
  39. Lessons from the Monckton/Plimer debate
    Here's one point I've been wanting to raise. If Monckton & the ACRIM model for TSI is correct (i.e. rising TSI over the last 30 years), then where is the corresponding Stratospheric warming? Even with the "intervention" of several major volcanic eruptions in the 1990's, stratospheric temperatures have still been trending *downward*. Like rising tropospheric temperatures, this stratospheric cooling is consistent with the Greenhouse Gas theory of recent climate change. Odd, then, how observed trends/phenomena seem to support, & reinforce, AGW theory-whilst we're still waiting for any evidence that supports the "theories" of Plimer, Monckton et al.
  40. Lessons from the Monckton/Plimer debate
    EdB, and before you think that Wegman was *impartial* and credible, go over to Deepclimate.org and do some reading there.
    Response: Keep in mind that those pages on Deep Climate will disappear into the archives long after people will read your comment - it's always recommended to post direct links to the relevant pages. Eg: Very interesting posts and the discussion comments are also worth a read, particularly one of the principals in the analysis drops by and presents their views in a surprisingly forceful fashion.
  41. Lessons from the Monckton/Plimer debate
    Well yes, but you're making three illogic arguments Peter. (i) Upper tropospheric water vapour concentrations aren't simply a consequence of lightning-associated atmospheric convection. These processes promote the transport of water to the high troposphere, but it's the upper tropospheric temperature that dominates the equilibrium UTWV concentrations. That's what Price and Asfur show in their 2006 paper (see link in my post just above). Spikes in UTWV follow lightning with a lag on the timescale of around a day (as determined by correlating lightning activity with independent determination of UTWV) and drop again; according to Price and Asfur this may account for very short term variability but doesn't dominate the globally-averaged temperature-dependent levels of UTWV. In other words UTWV can rise without an increase in lightning (or lightning-associated increased convective water vapour transport). (ii) The Schumann resonance method is very nice, and Price and Asfur propose this as a means of assessing daily variability of regional upper tropospheric water vapour, although their paper (Price and Asfur, 2006) has some caveats about its applicability. But it's illogic to assert that the Schumann resonance must increase in order for the water vapour feedback to be validated. That's a non-sequitur (see (i)). Lightning is expected to increase somewhat in a warming world, and Pinto and Pinto have observed this in their analysis over Brazil, but this issue certainly isn't settled. Pinto and Pinto, and Price and Asfur discuss the uncertainties in their papers; you haven't given us insight into the source of your certainty..It certainly can't arise from the work of the scientists that you cite. (iii) On this thread and the last one on tropospheric water vapour, you are taking some rather tenuous analyses, analyses that the scientists themselves are completely upfront about the uncertainties and their potentially premature nature....and ignoring all of this. Neither the Pinto's not Price and Asfur consider that their analyses are incompatible with expectations from physics and models (the Pinto's consider that their data are consistent with expectations from models). Price and Asfur don't consider that their analysis (Schumann resonance and all) has very much at all to say about the response of UTWV in a warming world, 'though they do consider that they might be able to get a handle on UTWV variability on a daily time scale. The bottom line is that it is possible ('though not completely straightforward!) to determine tropospheric water vapour levels using satellites. These data are consistent with expectations (water vapour rises as the upper troposphere warms). Likewise, despite the considerable problems with radiosondes, reanalysis of the radiosonde water vapour record doesn't give any reason to discount the interpretations from satellite data and models. One should consider all the evidence, uncertainties and all, before attempting grand conclusions.
  42. Lessons from the Monckton/Plimer debate
    @56. I do not follow your logic concerning the increase of temperature and lightning and computer models. The reality is that, globally, the planet warmed by almost 1 C in the past 130 years or so. Using your flawed logic (which seems to be based on results of a paper by Pinto and Pinto) there should have been a 30-40% increase in lightning flashes across the globe in response to the 1 C warming--maybe there has been, we just do not have a long enough data record to say so-- we do not have 130 years of reliable global lightning data. Anyhow, just b/c recent trends in global Schumann resonance has allegedly shown no long term increases in recent decades (no citation provided) we are meant to conclude that 1) The warming has not happened, and 2) This somehow means the AGCMS are all wrong. There are many other reliable metrics that all point to the planet having warmed, and lightning is not necessarily the best suited for that purpose for reasons I provided earlier on this thread. As for your claim that AGCMs suggest that lightning activity will increase, you seem to be incorrectly referring to the work of Price and Rind (1994, JGR), their model simulations indicated a 30% increase in global lightning for a DOUBLING of CO2-- not a 1 C increase in temperature as you suggest. Also, we are a long ways off doubling CO2. I could not find the Pinto and Pinto paper to which you are referring (correct citation please); most of their other work seems to have been done over small study areas in Brazil. Crook (1996, Monthly Weather Review) investigated the impacts of small changes of moisture and temperature the PBL on convective initiation (CI) and t'storm intensity. CI is much more complex than you seem to think. Did you read my earlier post? Warming over the Sahara is not going to produce thunderstorms unless there is sufficient low-level moisture, that is the limiting factor there, not temperature. Warming alone is not a sufficient condition to trigger a thunderstorm. There are other complicating factors, such as the fact that the entire troposphere is warming, and this affects the amount of CAPE and laspe rates (e.g., Del Genio 2007, GRL). Also, wind shear regimes are changing as the planet warms and this affects the longevity of the thunderstorms. The ad hoc adjustments to which you are referring are no such thing. If you are referring to the ARGO floats, then there was a very good reason for the adjustments, a faulty sensor. The nature of the error is known and has been quantified and has been corrected for accordingly. I'm sorry, this is not the "aha, got you" moment that you were hoping for. There have been many, many people who have claimed to have found the nail in the coffin of AGW, and none of them have succeeded yet. PS: Reeve and Toumi (2007; QJRMS) conclude that: "Data from the Optical Transient Detector lightning sensor are analysed to investigate the hypothesis that global lightning activity will increase should the average global temperature increase. It is shown that changes in global monthly land lightning activity are well correlated with changes in global monthly land wet-bulb temperatures. the correlation is strongest in the northern hemisphere and weak in the southern hemisphere. the conclusion is that a high land-area to sea-area ratio is necessary for a good correlation. Contrary to expectation, the tropics show no correlation. the results predict that a change in the average land wet-bulb temperature of the globe of just 1K would result in a change in lightning activity of about 40%." Also: Watkins et al. (1998; GRL) found a weak linear increase in global lightning activity between 1971 and 1996, and attributed that increase to more lighting over S. America.
  43. Lessons from the Monckton/Plimer debate
    For the record, there is not necessarily any conflict with suggesting that climate is insensitive and that natural variations are(primarily) responsible for the climate change or whatever. It simply requires that the (effective) value of the natural forcings be higher than the consensus estimates. While you would have to ask each man the specifics of their position, to assume that because they argue these positions, they contradict one another does not follow. Cheers, :)
  44. Berényi Péter at 10:39 AM on 31 January 2010
    Lessons from the Monckton/Plimer debate
    chris, it is not lightning that transfers water vapor to upper troposphere, but deep convection. Which also works as an electrostatic generator, hence the lightning connection. Vapor transport by tropical deep convection dominates upper troposphere humidity all over the globe. This is how lightning activity is related to humidity up there. Global integrated lightning activity is measured by Schumann resonance amplitudes. It is a sensitive device, for there are about fifty lightning events/sec on earth, so excitation of the lowest 8-30 Hz modes is a quasi-continuous process not subject to serious statistical fluctuations. No long term trend in SR, no enhancement of tropical deep convection, no increase in upper troposphere specific humidity, water vapor feedback can't be strong positive. You have a problem which would not go away by hand waving. "As you did on the other thread about tropospheric water vapour" It is not finished there, just discontinued. Specific humidity even at 700 hPa is decreasing slightly as measured by radiosondes. It is not a level where instrumental problems are manifest. http://www.skepticalscience.com/news.php?p=2&t=68&&n=117#7377
  45. On the reliability of the U.S. Surface Temperature Record
    sbarron2000: Take the max and min data shown, and take the average. That'll pretty much suffice. As for homogenisation: Again, I haven't taken the time to appreciate mechanics of the new pairwise algorithm yet, but as far as I'm concerned, the proof is in the pudding. After homogenisation, the 'poor' stations look just like the 'good', the liquid-in-glass look pretty much like the MMTS, and they all look like the US CRN network (which were purposefully sited ideally some time back). Seems like it's doing OK to me. And again, you'll see the major adjustment to the 'good' stations here was TOB, which is separate from the pairwise homogenisation.
  46. Lessons from the Monckton/Plimer debate
    Berenyi Peter, Wikipedia says "A strong link between global lightning and global temperature has not been experimentally confirmed as of 2008." Here are some peer-reviewed articles backing up that summary: Williams (2009, in Atmospheric Research) wrote in section 11, "Global circuit response to climate change," "The global circuit response to temperature change on still longer time scales remains an outstanding question (Williams, 2005, Satori et al., 2008). The best current evidence is that the global circuit is stable on long time scales, but the quantitative record is quite short, about half a century (Markson, 2007).... Lightning detection networks are often varying with time (addition of sensors, improvements in signal processing, etc) and this can complicate assessments of long-term trends." Williams (2005, in Atmospheric Research) wrote in the abstract "lightning is responsive to temperature on many time scales, but the sensitivity to temperature appears to diminish at the longer time scales." In the body of the article, "The evidence that lightning responds positively to temperature on all of the foregoing time scales does not guarantee a pronounced global circuit response to temperature. The key issue here is convective adjustment."
  47. Lessons from the Monckton/Plimer debate
    re #27/36 Berényi Péter "Once again. Forget communication & messages, it is not the scientist's field of expertise. Go for truth instead." Careful with attempts at "truth" Peter. As you did on the other thread about tropospheric water vapour, you're attempting to bypass the essential element of scientific enquiry which is evidence. Attempts at "truth" might be used to bolster weak, non-scientific positions, but it’s usually obvious if these don't accord with the evidence. That's the case with your lightning/upper tropospheric water vapour (UTWV) idea. I think you've misunderstood the papers of the scientists that you cite (O. Pinto Jr. and I.R.C.A. Pinto; and C. Price and M. Asfur). The essential point is not that enhanced lightening is expected in a warming world due to enhanced UTWV; in fact lightning is a means of (temporarily) enhancing UTWV (and aiding equilibration of water vapour in the UT), and the use of lightening as a proxy for UTWV should be seen in that light; it’s a potential means of determining the variability in UTWV. That’s clear from the recent papers of your scientists: e.g.: Pinto O and Pinto IRCA (2008) On the sensitivity of cloud-to-ground lightning activity to surface air temperature changes at different timescales in Sao Paulo, Brazil J. Geophys. Res. 113, D20123 http://www.agu.org/pubs/crossref/2008/2008JD009841.shtml These authors describe the expectation that lightning should increase in a warming world, and show that their own data from Brazil is consistent with models in predicting enhanced lightning above an enhanced surface warmth in the decades from 1950-1990. They point out that there isn’t good evidence for long term global lightning trends, but state that this may be due to limited and localized analyses and the fact that lightning predominates in the tropics whereas warming as dominated in the temperate and polar regions. These authors say nothing about the relationship between lightning and UTWV other than to point out that Price and Asfur have attempted to relate variability in UTWV to lightning (i.e. lightning is the cause of temporarily enhanced UTWV since the associated phenomena aid in transporting water vapour to high altitudes). This is very clearly stated in the recent papers of Price and Asfur. For example: Price C (2009) Will a drier climate result in more lightning? Atmos. Res. 91, 479-484
    Previous studies have indicated that increased lightning activity will moisten the upper troposphere ([Price, 2000] and [Price and Asfur, 2006a]). Hence, a drier surface resulting in a wetter upper atmosphere also appears to present a contradiction. However, in a warmer climate the enhanced evaporation from the oceans, together with the increased moisture-holding capacity of the atmosphere, leads to higher specific humidities in the atmosphere. When thunderstorms develop in this moister environment, there is more water vapor available for transport aloft into the upper troposphere. Since the upper troposphere is naturally extremely dry, increasing the intensity of thunderstorms in a warmer climate will indeed moisten the upper troposphere, even though the surface layer may be drier due to enhanced evapo-transpiration, and/or decreases in the amount of rainfall.
    And Price and Asfur, point out that there is a good match between lightning activity and the subsequent change in UTWV (due to the causality indicated above), and therefore lightning activity could be a potentially useful means of estimating UTWV variability, which they assess by comparing lightning data with independent UTWV measures from NCEP. Price and Asfur are in agreement with the evidence that increased global warming has resulted in enhanced UTWV; their analysis is a potential means of assessing daily variability in UTWV (over continents but not over oceans): Price C, Asfur M (2006) Can lightning observations be used as an indicator of upper-tropospheric water vapor variability? Bull. Amer. Met. Soc. 87, 292-298 http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2FBAMS-87-3-291 So global lightning isn’t a proxy for global UTWV. However since lightning is part of the atmospheric phenomenon that facilitates transport of tropospheric water to the UT, thunderstorm and lighting variability are expected to result in consequent UTWV variability in the short term (Price and Asfur consider it debatable whether the lighting – UTWV response will be manifest on changing the temporal scale from daily to monthly, seasonally or longer term), and that’s the basis for their analysis. Of course if we want to determine UTWV we really have to do the hard work of careful satellite monitoring or get to grips with the (so far imperfect) radiosonde reanalyses….
  48. Lessons from the Monckton/Plimer debate
    EdB, the ultimate arbiter of scientific analysis is time and the cauldron of subsequent research and critique. If one is interested in the paleoclimate of the last millenium or two, one looks at the scientific evidence (lots of this presented in recent posts on this thread). Mann's original analysis has been hugely stimulating of an entire scientific field, and the subsequent analysis using a range of methods, has come up with broadly similar conclusions about the anomalous nature of late 20th century and contemporary warming. If Mann was so wrong, how come he seems to have been right? That's the beauty of the scientific method Ed. Reality supercedes politics. It would be unfortunate to fixate on a political "enquiry", and ignore the reality of a wealth of scientific data...
  49. Berényi Péter at 08:41 AM on 31 January 2010
    Lessons from the Monckton/Plimer debate
    Riccardo, Pinto & Pinto have found that a single degree centigrade of local surface temperature change is enough to increase lightning activity by as much as 30-40%, independent of timescale. An effect of this magnitude is also predicted by climate models. The coupling is prominent, one can not possibly miss it, provided warming occurs indeed. On the other hand, via Schumann resonance no increase in global integrated lightning activity is observed on multidecadal scales. It follows, that both temperature trend reconstructions and mainstream climate models are in serious trouble. Indirect measurement is fine as long as the measurement process and device is tightly controlled and the physics is understood. Neither one of these assumptions hold for the kinds of indirect measurements AGW theory is based on. OHC would be a good indicator if it were measured. In fact it is only measured with reasonable resolution since late 2003 and only for the upper 750 m or so of the oceans. Not much increase is observed for this period, all else is the usual mess of ad hoc "adjustments". Measuring the low frequency modes of Schumann resonance is a beautiful hack. It effectively uses the entire Earth as a high precision measurement device. It is not an effect masked by all kinds of biases, spurious noise sources, instrument changes, calibration problems and the like. Also, long term measurement projects are not controlled by the climate crowd, but geophysicists. I wonder what should happen to force you to consider constant UTRH climate models getting falsified. If no conceivable state of affairs is sufficient to do that, the models are so slippery, they have no scientific merit whatsoever. As for being harsh. Please, do that, I am not touchy. In science going for truth is a better predisposition than going for PR exploits, influence, glory, power, money and the like. If it is arrogant, so be it.
  50. Lessons from the Monckton/Plimer debate
    EdB this site is pretty good at focusing on the science, and you’re not going to make much headway with that stuff. I wonder if you’d really be happy with a world in which science was “decided” by political committees! In fact there have been a large number of paleoproxy analyses of past temperatures since Mann's original papers. These pretty uniformly support the essential conclusions of the 1998/9 Mann et al reconstructions, with no evidence (in N Hemisphere reconstructions) of any periods during the past couple of millennia that were warmer than the temperatures around the middle of the 20th century (i.e. the evidence indicates that the contemporary N. hemisphere is already around 0.6-0.9 oC warmer than during the warmest period of the last 2000 years). All of the published paleoreconstructions place the late 20th century and contemporary warming as being anomalous in the context of the last two millennia much as Mann et al proposed in 1998. The paleoproxy data is archived here, and there’s no excuse in not addressing the scientific evidence that supports this conclusion: http://www.ncdc.noaa.gov/paleo/recons.html Otherwise, it’s difficult to understand your posts. I’ve just looked in the database for papers by the McIntyre person that you have mentioned and there simply isn’t anything there that addresses this subject (apart from a few paragraphs of unsubstantiated complaints against Mann et al's 2008 paper in PNAS). Wahl and Ammann published an enormously detailed paper that essentially validated the Mann et al proxy analysis in relation to detailed methodologies, and demonstrated that the McIntyre critique was without merit: Wahl ER, Ammann CM (2007) Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence Climatic Change 85, 33-69 Your McIntyre chap hasn’t responded in the scientific literature, so clearly there’s nothing substantively wrong with the Mann et al or Wahl and Ammann’s analyses that warrents a critical analysis in the scientific literature. In any case this is very, very old news and we don’t have to keep on pretending that all of our understanding of paleoclimate rests on a paper from 12 years ago! If we're interested in the science we really should be addressing the evidence.

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